Lamp swivel assembly with rotational limiting means



Aug. 11, 1964 Y R. A. GRAY, JR 3,144,263

LAMP SWIVEL ASSEMBLY WITH ROTATIONAL LIMITING MEANS Filed Dec. 9, 1960United States Patent 3,144,263 LAMP SWIVEL ASSEMBLY WITH ROTATIONALLIMITING MEANS Robert A. Gray, In, Port Huron, Mich, assignor to MuellerBrass (30., Port Huron, Mich., a corporation of Michigan Filed Dec. 9,1960, Ser. No. 74,799 1 Claim. (Cl. 285-269) This invention relates tolamp swivel assemblies and the like, and more particularly to swivelsfor preventing twisting of electrical wires in lamps where the shade orreflector is permitted a universal adjustment movement.

It is an object of the present invention to provide a novel and improvedconstruction which permits a universal swiveling movement of thereflector but will prevent excessive twisting of the wires which mightoccur if the reflector were rotated more than 360 or a substantialportion thereof.

It is another object to provide a novel and improved lamp swivel of theabove nature which is inexpensive to fabricate and has relatively fewparts, thus increasing its reliability over long periods of use.

Other objects, features and advantages of the present invention willbecome apparent from the subsequent description, taken in conjunctionwith the accompanying drawings, in which:

FIGURE 1 is a side elevational view in cross-section showing thecomponents of the lamp swivel in assembled position;

FIG. 2 is an end elevational view of the assembly looking in thedirection of the arrow 2 of FIG. 1;

FIG. 3 is an elevational view of the stop ring;

FIG. 4 is an elevational view of the swivel ring which also shows indot-dash lines the manner in which the flat surfaces of the swivel areengaged by the indentations on the swivel ring;

FIG. 5 is a top plan view of the swivel ring viewed in the direction ofthe arrow 5 of FIG. 4; and

FIG. 6 is a fragmentary cross-sectional View taken along the line 6-6 ofFIG. 1 and showing the coacting elements of the stop ring and swivelring in engaged position.

In general terms, the invention comprises a hollow elongated bodyadapted to be mounted on a lamp base, and a swivel of generallyspherical shape disposed within the body and adapted to support a bulbsocket. A swivel seat is disposed within the body and is urged againstthe swivel by a spring, a retaining member mounted on the body holdingthe swivel in place. A stop ring having an inwardly extending projectionis secured between the retaining member and body, and a swivel ring ismounted on the swivel and has a projection coacting with the stop ringprojection to prevent rotation of the swivel more than 360.

Referring more particularly to the drawings, the lamp swivel isgenerally indicated at 11 and comprises a body 12 of generally taperedtubular shape having an internally threaded portion 13 at one end forthe reception of a nipple 14 which may be part of a lamp base (notshown). Nipple 14 is adapted to receive one or more electrical conduitsindicated by dot-dash lines at 15 to be connected to a bulb socket.

The other end of body 12 has an externally threaded portion 16, and thecavity 17 within the body is provided with an intermediate annularshoulder 18. A swivel 19 is disposed within cavity 17. This swivel has agenerally spherical shape with a central passage 20 for the reception ofwires 15 and with oppositely disposed flat surfaces 21. Swivel 19extends outwardly from body 12, and its outer end is provided with anexternally threaded portion H 22 for the reception of a bulb socketindicated partially by dot-dash lines at 23. One side 24 of swivelportion 22 3,144,253 Patented Aug. 11, 1964 may be flat to receive a setscrew (not shown) conventionally carried by the bulb socket, and ashoulder 25 is disposed between the spherical portion and the threadedportion of swivel 19 to properly locate the bulb socket when it isscrewed onto portion 22.

A helical coil compression spring 26 is disposed within cavity 17, oneend of this spring engaging shoulder 18. A swivel seat 27 of annularshape is partially disposed within spring 26, the portion of this seatfacing swivel 19 being flared outwardly so as to receive the adjacentspherical portion of the swivel.

A retaining member 28 having an internally threaded portion 29 isthreaded onto body portion 16. The end of retaining member 28 has aninwardly extending shoulder portion 31 the inner edge of which is ofsufficiently small diameter to engage the spherical portion of swivel 19so as to prevent the swivel from being pushed out of cavity 17 by spring26. An annular groove 32 is formed in shoulder 31 facing body 12, and astop ring 33 is disposed within the outer portion of this groove. Thethickness of ring 33 is substantially less than the width of groove 32,and the ring is held securely in position when retaining member 29 isthreaded onto body 12. An inwardly extending projection 34 is formed onring 33, this projection being disposed within the inner portion ofgroove 32.

A swivel ring 35 is mounted on swivel 19, this ring being of generallycircular shape but having two oppositely disposed inwardly extendingindented portions 36 engaging flats 21 of the swivel. As in the case ofstop ring 33, ring 35 may be fabricated as a stamping, or it may be madefrom flat stock if desired. The axial thickness of ring 35 is somewhatgreater than that of ring 33, and a projection 37 on the ring extendsaxially into the inner portion of groove 32, the thickness of both rings33 and 35 together being approximately equal to the width of groove 32as seen in FIGURE 1.

In operation, the assembled lamp swivel is so constructed that swivelmember 19 may be pivoted on an axis at right angles to the plane of thepaper in FIG. 1, or may be rotated on its own axis so that a universaladjustment of the bulb socket 23 is permitted. Swivel 19 will be held inits adjusted position by its frictional engagement with seat 27 andshoulder 31, and its movements will be unhindered by excessive friction,since coil spring 26 does not directly engage the swivel.

A shoulder 33 is formed in cavity 17 surrounding swivel 19, and the edgeof ring 35 opposite that from which projection 37 extends is adapted toengage this shoulder. The axial thickness of ring 35 is slightly lessthan the distance between shoulder 38 and the bottom of groove 32 whenretaining member 28 is tightened with ring 33 in place.

Movement of swivel 19 on its axis transverse to the paper in FIG. 1 willbe limited by the engagement of juncture 39 between shoulder 25 andswivel portion 19 of the swivel with the edge of aperture 41 onretaining member 28. The rotational movement of swivel 19 on its ownaxis will be limited by engagement of projection 37 of ring 35 withprojection 34 of ring 33, as seen in FIG. 6. This will prevent excessivetwisting of wires 15 which might otherwise occur if unlimited rotationalmovement of the swivel were permitted.

It will thus be seen that a novel and improved lamp swivel constructionhas been provided which has relatively few parts, these parts beingcapable of fabrication by simple and inexpensive machining or stampingmethods. The unit permits wide latitude in adjusting a lamp or similardevice, but is at the same time reliable and not subject to easy damageduring long periods of use.

While it will be apparent that the preferred embodiment of the inventiondisclosed is well calculated to fulfill the objects above stated, itwill be appreciated that the invention is susceptible to modification,variation and change without departing from the proper scope or fairmeaning of the subjoined claim.

What is claimed is:

In a lamp swivel assembly or the like, a body of generally tubularshape, a swivel having a generally spherical portion disposed within oneend of said body and a mounting portion extending outwardly therefrom,retaining means fixed to said one body end and having an annular 10groove between said retaining means and said body, a stop ring fixedlydisposed within one portion of said groove and having a radiallyextending projection extending into the other portion of said groove, acompression coil spring Within said body, an annular seat engaged bysaid spring 1 and having a flared portion receiving said sphericalswivel portion, a swivel ring separate from said fixed retaining meansmounted on said spherical swivel portion and rotatable therewith, a pairof oppositely disposed flat surfaces on said spherical swivel portion, apair of indented portions on said swivel ring engageable with said flatsurfaces, an annular shoulder in said body engageable by one edge ofsaid swivel ring, and a projection extending from the other edge of saidswivel ring and disposed Within said groove, said projections coactingto limit the rotational movement of said swivel.

References Cited in the file of this patent UNITED STATES PATENTS2,324,741 Svabek July 20, 1943 2,621,882 Fletcher Dec. 16, 19522,859,983 May Nov. 11, 1958 2,910,310 Mulac Oct. 27, 1959 3,012,798Berger Dec. 12, 1961 3,037,799 Mulac June 5, 1962

